Prerequisites for RPR

Restrictions for RPR

General RPR Restrictions

•When a redundant supervisor engine is in standby mode, the two Gigabit Ethernet interfaces on the standby supervisor engine are always active.

•Supervisor engine redundancy does not provide supervisor engine mirroring or supervisor engine load balancing. Only one supervisor engine is active.

•Configuration changes made through SNMP are not synchronized to the standby supervisor engine. After you configure the switch through SNMP, copy the running-config file to the startup-config file on the active supervisor engine to trigger synchronization of the startup-config file on the standby supervisor engine.

•Supervisor engine switchover takes place after the failed supervisor engine completes a core dump. A core dump can take up to 15 minutes. To get faster switchover time, disable core dump on the supervisor engines.

•You cannot perform configuration changes during the startup (bulk) synchronization. If you attempt to make configuration changes during this process, the following message is generated:

Config mode locked out till standby initializes

•If configuration changes occur at the same time as a supervisor engine switchover, these configuration changes are lost.

Hardware Restrictions for RPR

•Cisco IOS supports redundant configurations where the supervisor engines are identical. If they are not identical, one will boot first and become active and hold the other supervisor engine in a reset condition.

•Each supervisor engine must have the resources to run the switch on its own, which means all supervisor engine resources are duplicated, including all flash devices.

•Make separate console connections to each supervisor engine. Do not connect a Y cable to the console ports.

When the switch is powered on, RPR runs between the two supervisor engines. The supervisor engine that boots first becomes the RPR active supervisor engine. The route processor (RP) and Policy Feature Card (PFC) become fully operational. The RP and PFC on the standby supervisor engine come out of reset but are not operational.

In a switchover, the standby supervisor engine become fully operational and the following occurs:

•All switching modules power up again

•Remaining subsystems on the RP (including Layer 2 and Layer 3 protocols) are brought up

•Access control lists (ACLs) are reprogrammed into supervisor engine hardware

Note In a switchover, there is a disruption of traffic because some address states are lost and then restored after they are dynamically redetermined.

Supervisor Engine Configuration Synchronization

Note Configuration changes made through SNMP are not synchronized to the standby supervisor engine. After you configure the switch through SNMP, copy the running-config file to the startup-config file on the active supervisor engine to trigger synchronization of the startup-config file on the standby supervisor engine.

During RPR mode operation, the startup-config files and the config-register configurations are synchronized by default between the two supervisor engines. In a switchover, the new active supervisor engine uses the current configuration.

Configuring RPR Mode

Configures RPR. When this command is entered, the standby supervisor engine is reloaded and begins to work in RPR mode.

This example shows how to configure the system for RPR:

Router> enable

Router# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)# redundancy

Router(config-red)# mode rpr

Router(config-red)# end

Router# show running-config

Router# show redundancy states

Synchronizing the Supervisor Engine Configurations

During normal operation, the startup-config and config-registers configuration are synchronized by default between the two supervisor engines. In a switchover, the new active supervisor engine uses the current configuration.

Note Do not change the default auto-sync configuration.

Displaying the Redundancy States

To display the redundancy states, perform this task:

Command

Purpose

Router# show redundancy states

Displays the redundancy states.

This example shows how to display the redundancy states:

Router# show redundancy states

my state = 13 -ACTIVE

peer state = 8 -STANDBY HOT

Mode = Duplex

Unit = Primary

Unit ID = 1

Redundancy Mode (Operational) = Route Processor Redundancy

Redundancy Mode (Configured) = Route Processor Redundancy

Split Mode = Disabled

Manual Swact = Enabled

Communications = Up

client count = 11

client_notification_TMR = 30000 milliseconds

keep_alive TMR = 9000 milliseconds

keep_alive count = 0

keep_alive threshold = 18

RF debug mask = 0x0

In this example, the system cannot enter the redundancy state because the second supervisor engine is disabled or missing:

Router# show redundancy states

my state = 13 -ACTIVE

peer state = 1 -DISABLED

Mode = Simplex

Unit = Primary

Unit ID = 1

Redundancy Mode (Operational) = rpr

Redundancy Mode (Configured) = rpr

Redundancy State = Non Redundant

Maintenance Mode = Disabled

Communications = Down Reason: Simplex mode

client count = 11

client_notification_TMR = 30000 milliseconds

keep_alive TMR = 4000 milliseconds

keep_alive count = 0

keep_alive threshold = 7

RF debug mask = 0x0

Copying Files to the RP

Use the following command to copy a file to the bootflash: device on an active RP:

Router# copysource_device:source_filenamebootflash:target_filename

Use the following command to copy a file to the bootflash: device on a standby RP: